Amine imides are known as useful compounds for sources of polymerizable compounds such as polyurethane resins and polyurea resins, as well as for curing agents, cleaners, surfactants, surface treating agents, pharmaceutical or agrochemical intermediates, etc.
Amine imides are characterized by the fact that they undergo dissociation by the cleavage of the nitrogen-nitrogen (N—N) bond in their molecular structure by heat treatment, to produce an isocyanate and a tertiary amine. The isocyanate reacts with organic compounds bearing such functional groups as hydroxyl or amino groups, and the tertiary amine is highly basic and therefore acts as a curing agent for epoxy or other resins. Because of these properties, amine imides have been utilized as, for example, latent curing agents for epoxy resins.
Dissociation of an amine imide, however, generally requires temperatures as high as 130° C. or above. This makes the compound difficult to be used as a latent curing agent for epoxy resin compositions for use as adhesions, coatings and electric/electronic materials, where curing should be effected at relatively low temperatures. Thus, demand has been growing for amine imides that can cure epoxy resin compositions at lower temperatures, i.e., offer high low-temperature curing ability.
Examples of amine imides known to be capable of curing epoxy resin compositions at lower temperatures include those having an organic group in which a hydroxyl group is bonded to a carbon atom to which a carbonyl carbon atom is bonded (see, e.g., Patent Document 1), and those having one or two hydroxyl groups in their molecular structure (see, e.g., Patent Document 2).
Patent Document 3 discloses amine imides in which an olefinic double bond is introduced to the carbonyl carbon atom of the amine imide group. Patent Document 3 also discloses amine imides having hydroxyl groups in addition to an olefinic double bond and describes that the hydroxyl groups may react with isocyanates. However, the amine imides are disclosed as being polymerizable compounds (monomers) which polymerize under anaerobic conditions, not as curing agents used to polymerize or cure other polymerizable compounds.    Patent Document 1: Japanese Patent Application Laid-Open No. 2000-229927    Patent Document 2: Japanese Patent Application Laid-Open No. 2003-096061    Patent Document 3: U.S. Pat. No. 4,005,055